Effect of SiO₂ and Post-Annealed Ga₂O₃ Buffer Layers on Ga₂O₃ Thin Film Growth and Properties

This study explores the impact of SiO2 and β-Ga2O3 buffer layers on the synthesis and properties of β-Ga2O3 thin films deposited on n-type Si (100) substrates via sol–gel spin coating. Structural, morphological, and optical properties were characterized using X-ray diffraction, scanning electron microscopy, and UV–vis spectroscopy. Films on β-Ga2O3 buffers exhibit significantly enhanced crystallinity, reduced lattice strain, and lower defect density compared to SiO2/Si and direct Si substrates. Morphological analysis reveals well-defined, coalesced grains, while optical measurements indicate an improved bandgap, reflecting superior film quality. These findings underscore the efficacy of β-Ga2O3 buffers in mitigating lattice mismatch, advancing the development of high-quality β-Ga2O3 films for high-power electronics and UV optoelectronic applications.